Forget spending money on any ROV training course. Spend your money increasing your electrical, electronic, fibre optic, high voltage qualifications. Get recognised national qualifications (HNC City and Guilds etc for example in UK). These qualifications will stand you in good stead for any ROV job as well as many other jobs in the world.
ROV training courses are not regulated, quite often not worth the paper they are printed on and are no good for any other jobs apart from ROVs. Hence national qualifications are much better value.
There are many unemployed ROV pilots with years and decades of experience about just now, with the price of oil being so low it is a difficult market to start off in.
.
.
